Pre- and post-epididymal sperm are being isolated from rams and their biochemical characteristics are being compared. Specific comparisons include: role of cAMP in the initiation of sperm motility; energy requirements of sperm cell types; chemical and physical characteristics of sperm membranes. BIBLIOGRAPHIC REFERENCES: Margarett Cascieri, R.P. Amann and Roy H. Hammerstedt, "Alteration of Metabolism in Bovine Pre- and Post-Epididymal Sperm by CAMP." Fed. Proc. (1974) 33, Abs.